This invention relates to catheter-based systems for treatment of chronic total occlusions in tubular vessels by revascularization of the occlusion.
Chronic total occlusions in arteries occlude the lumen and prevent blood from flowing to tissue that is distal to the occlusion. Total occlusions have been treated by using laser energy or an atherectomy device to create a channel through the occlusions, through an endarterectomy procedure to open the occluded artery to remove the occlusion, or bypassing the occlusion in, for example, coronary artery bypass grafting. Each of these methods presents challenges to the physician. In the case of using laser energy or an atherectomy device to create a channel, the delivery of the device may be difficult and the resulting surface does not mimic that of a healthy artery. In the case of a bypass around the occlusion, the physician may use a synthetic graft, a vein graft or an artery graft. Each of these grafts has a limited lifetime. Moreover, a synthetic graft does not have a blood contacting surface with the characteristics of a natural artery and there is a limited supply of suitable homologous vein and artery grafts.
In one general aspect, a catheter delivery system for delivering a treatment substance to an occlusion in a lumen of a tubular vessel includes a tubular catheter and a treatment substance. The tubular catheter includes a central lumen passing between a proximal end and a distal end adjacent to an inflatable balloon. The treatment substance may be in a form that is configured to be deliverable through the central lumen of the catheter into the lumen of the tubular vessel and to solidify in the vessel.
Embodiments of the catheter delivery system may include one or more of the following features. For example, the treatment substance deliverable using the catheter delivery system may include one or more of a fibrin glue, a biodegradable material that is deliverable in liquid form and solidifies after delivery into the lumen of the tubular vessel, an inflammatory agent, a dissolving agent configured to dissolve the occlusion, an angiogenesis agent for revascularizing the occlusion, an anti-restenosis agent, a gene therapy agent, an anti-coagulant agent, and a curable material. The treatment substance may be in a liquid form or a semi-liquid form. The fibrin glue can function as a vehicle to provide the other treatment substances.
The tubular catheter may further include a light delivery fiber having a distal end adjacent to the distal end of the tubular catheter and a proximal end adjacent to the proximal end of the tubular catheter. The treatment substance may include a light curable material. Providing light to the light delivery fiber cures the light curable material. The inflatable balloon may have a proximal end and a distal end and the distal end of the inflated balloon forms a surface that is generally perpendicular to a longitudinal axis of the tubular vessel. The balloon is radially expanded against the walls of the tubular vessel.
The system may further include a wire having a sharpened tip at a distal end of the wire and configured to be delivered through the tubular catheter. The sheath prevents the sharpened tip from damaging or puncturing the tubular catheter. The system may further include a sheath configured to receive the wire and to pass through the central lumen of the tubular catheter for delivering the wire through the tubular catheter. The system may still further include a second sheath, a second wire and at least one treatment plug. The second wire and the treatment plug are received in the second sheath. The second wire has an end configured to advance the treatment plug through the sheath when the second wire is advanced through the sheath. The treatment plug is delivered by withdrawing the sheath while holding the wire in a fixed position.
The catheter delivery system may further include a wire having a sharpened tip at a distal end of the wire that is deliverable through the tubular catheter into a wall of the tubular vessel. The catheter delivery system may also include a sheath that is configured to receive the wire and to be passed through the central lumen of the tubular catheter for delivering the wire through the tubular catheter. The sheath includes a distal end that is configured to direct the distal end of the wire into the wall of the tubular vessel. The wire may have a curved shape for directing the sharpened tip of the wire into the wall of the tubular vessel.
The catheter delivery system may further include a heating catheter deliverable through the tubular catheter and having a distal end configured to produce a heating effect and the treatment substance may include a heat curable material. The heating catheter may produce a heating effect through RF heating or resistive heating.
Another general aspect includes a method for delivering one or more treatment substances to a lumen of a tubular vessel to treat an occlusion of the tubular vessel. The method includes providing a catheter delivery system including a tubular catheter having an inflatable balloon, inserting the tubular catheter into a mammalian vasculature, advancing the tubular catheter through the vasculature until the tubular catheter is adjacent to the occlusion in the tubular vessel, inflating the inflatable balloon, and injecting a first treatment substance into and through the tubular catheter. The catheter system used in the method includes a tubular catheter having a central lumen passing between a proximal end and a distal end adjacent to the inflatable balloon. The treatment substance is in a form that is configured to be deliverable through the central lumen of the catheter into the lumen of the tubular vessel and to solidify in the vessel. When employing the method, inflating the inflatable balloon creates a first volume within the tubular vessel that is defined between the inflated balloon and the occlusion and injecting treatment substance into and through the tubular catheter substantially fills the first volume with the treatment substance.
Embodiments of the method may include one or more the following features. For example, the method may further include withdrawing the tubular catheter away from the first treatment substance when the first treatment substance has solidified. The method may still further include inflating the inflatable balloon to define a second volume defined between the first treatment substance and the inflated balloon and injecting a second treatment substance into and through the tubular catheter such that the second treatment substance substantially fills the second volume. The second treatment substance is configured to solidify in the second volume. The treatment substance may be in a liquid form or a semi-liquid form.
The method then may still further include withdrawing the tubular catheter from the second treatment substance when the second treatment substance has solidified, inflating the inflatable balloon to define a third volume defined between the second treatment substance and the inflated balloon, and injecting a third treatment substance into and through the tubular catheter such that the third treatment substance substantially fills the third volume, whereby the third treatment substance is configured to solidify in the third volume. This process may be repeated using various treatment substances to form a series of different or repeating treatment substances within the tubular vessel.
The treatment substance delivered in the method may include one or more of a fibrin glue, a biodegradable material that is deliverable in liquid form and solidifies after delivery into the lumen of the tubular vessel, an inflammatory agent, a dissolving agent configured to dissolve the occlusion, an angiogenesis agent, an anti-restenosis agent, a gene therapy agent, an anti-coagulant agent, and a curable material.
The inflatable balloon may have a proximal end and a distal end and the distal end of the balloon forms a surface that is generally perpendicular to a longitudinal axis of the tubular vessel when the balloon is inflated. The tubular catheter may further include a light delivery fiber having a distal end adjacent to the distal end of the tubular catheter and a proximal end adjacent to the proximal end of the tubular catheter and the first treatment substance includes a light curable material such that applying light to the light delivery fiber directs light onto the first treatment substance to cure the light curable material of the first treatment substance.
Another general aspect includes a method for delivering one or more treatment substances to an occlusion in a tubular vessel to treat the occlusion of the tubular vessel. The method includes providing a catheter delivery system for delivering a treatment substance to an occlusion in a lumen of a tubular vessel, the catheter system including: a tubular catheter having a central lumen passing between a proximal end and a distal end adjacent to an inflatable balloon, a wire having a sharpened tip at a distal end of the wire and configured to be delivered through the tubular catheter, and a treatment substance that is configured to be deliverable through the central lumen of the catheter into the occlusion of the tubular vessel. The tubular catheter is inserted into a mammalian vasculature and advanced through the vasculature until the distal end of the tubular catheter is adjacent to the occlusion in the tubular vessel. The balloon is inflated to firmly position the tubular catheter within the tubular vessel. The wire is inserted into the tubular catheter and advanced until the sharpened tip is adjacent to the occlusion in the tubular vessel. The wire then is further advanced such that the sharpened tip is inserted into the occlusion and forms a channel in the occlusion.
Embodiments of the method may include one or more of the following features. For example, a treatment substance may be injected into and through the tubular catheter such that the treatment substance is injected into the channel in the occlusion. The treatment substance may include a material configured to solidify in the channel in the occlusion. The tubular catheter may further include a light delivery fiber having a distal end adjacent to the distal end of the tubular catheter and a proximal end adjacent to the proximal end of the tubular catheter and the treatment substance may include a light curable material such that applying light to the light delivery fiber directs light onto the treatment substance to cure the light curable material of the treatment substance.
The method may further include inserting one or more treatment plugs into the channel in the occlusion and the catheter delivery system further includes a sheath, a second wire and at least one treatment plug. The second wire and the treatment plug are received in the sheath and the second wire has an end that is configured to advance the treatment plug through the sheath when the second wire is advanced through the sheath. Inserting the treatment plug into the channel includes advancing the sheath into the channel, advancing the second wire through the sheath to advance the treatment plug into the channel and withdrawing the sheath while leaving the second wire in a relatively fixed position when the treatment plug is in the channel.
Another general aspect includes a catheter system for delivering a treatment substance into an occlusion in a lumen of a tubular vessel. The catheter system includes a tubular catheter having a lumen passing between a proximal end and a distal end, a wire configured to be passed through the tubular catheter to create a channel in the occlusion, and a treatment substance for delivery through the tubular catheter into the occlusion to treat the occlusion.
The treatment substance delivered with the catheter system may include one or more of a fibrin glue, a biodegradable material that is deliverable in liquid form and solidifies after delivery into the lumen of the tubular vessel, an inflammatory agent, a dissolving agent configured to dissolve the occlusion, an angiogenesis agent, an anti-restenosis agent, a gene therapy agent, an anti-coagulant agent, and a curable material.
The wire may include a distal end having a sharpened tip and a proximal end having a gripping implement. The tubular catheter may include a distal end having a tapered tip and the tapered tip may have an inner diameter that is larger than an outer diameter of the wire. The tapered tip may have at least one eye hole passing through a wall of the tubular catheter.
Another general aspect includes a method of delivering a treatment substance to an occlusion. The method includes providing a tubular catheter having a lumen passing between a proximal end and a distal end, providing a wire having a proximal end and a distal end and being configured to be passed through the tubular catheter to create a channel in the occlusion, providing a treatment substance for delivery through the tubular catheter into the occlusion to treat the occlusion, inserting the tubular catheter into a mammalian vasculature, advancing the tubular catheter through the vasculature until the distal end of the tubular catheter is adjacent to the occlusion, inserting the wire into the tubular catheter, advancing the wire through the tubular catheter until the distal end of the wire is adjacent to the occlusion, further advancing the distal end of the wire into the occlusion to create a channel in the occlusion, withdrawing the wire from the occlusion and the tubular catheter, and injecting a treatment substance through the tubular catheter into the channel in the occlusion.
Embodiments of the method may include one or more of the following features. For example, the treatment substance may include one or more of an angiogenesis agent, a combination of angiogenesis agents, an occlusion dissolving agent, an anti-restenosis agent, and an inflammatory agent. The wire may include a distal end having a sharpened tip and a proximal end having a gripping implement. The tubular catheter may include a distal end having a tapered tip and the tapered tip may have an inner diameter that is larger than an outer diameter of the wire. The tapered tip may have at least one eye hole passing through a wall of the tubular catheter.
In another general aspect, a catheter delivery system for delivering a treatment substance to a lumen of a tubular vessel includes a tubular catheter and an expandable treatment stent. The tubular catheter includes a central lumen passing between a proximal end and a distal end that is adjacent to an inflatable balloon. The expandable treatment stent is mounted to the inflatable balloon for expansion and deployment by the balloon and includes an expandable stent component and a treatment substance component attached to the expandable stent component.
Embodiments of the stent may include one or more of the following features. For example, the treatment substance may include an inflammatory agent, a dissolving agent configured to dissolve the occlusion, at least one angiogenesis agent, an anti-restenosis agent, a gene therapy agent, and an anti-coagulant agent.
The system and methods can provide numerous advantages. For example, delivering the treatment substances and materials can stimulate collateral neo-angiogenesis formations so that distal ischemia can be reduced. The system and methods also can lead to a softening of the occlusion so that subsequently the occlusion can be passed and treated percutaneously with an angioplasty or an atherectomy device after accessing the distal lumen of the occlusion.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.